Remove Travis CI badge and improve dropdown selection handling

1. Removed broken Travis CI build status badge from README header

2. Enhanced dropdown selection on messages page:
   - Added explicit JavaScript change event handler
   - Added CSS to ensure proper text color and background
   - Added blur/focus to force visual update after selection
   - Added console logging for debugging

This should resolve the issue where selected recipient names weren't
displaying properly in the dropdown after selection.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/views/messages/index.html.erb

@@ -158,6 +158,14 @@ $(document).on('turbolinks:load', function() {
   makeActive();
 });
 
+// Explicitly handle dropdown selection to ensure display updates
+$('#message_receiver_id').on('change', function() {
+  var selectedText = $(this).find('option:selected').text();
+  console.log('Selected recipient:', selectedText);
+  // Force a visual update
+  $(this).blur().focus();
+});
+
 // Form submission with AJAX
 $("#submit_button").click(function(event) {
   event.preventDefault();
@@ -306,4 +314,19 @@ $("#submit_button").click(function(event) {
       justify-content: center;
     }
   }
+
+  /* Ensure dropdown displays selected value properly */
+  #message_receiver_id {
+    color: #212529;
+    background-color: #fff;
+  }
+
+  #message_receiver_id option {
+    color: #212529;
+  }
+
+  #message_receiver_id:focus {
+    border-color: var(--rg-success);
+    box-shadow: 0 0 0 3px rgba(6, 214, 160, 0.1);
+  }
 </style>